Line-height

Line-length

As for line length - golden ratio typography
claims that it should be proportional to line-height, which makes sense, but the equation they suggest
just doesn't make any sense.
A Smashing Magazine article
suggests that around 65 characters per line is ideal, but that most people go for more like 75.
65em / 1.618 (golden) = 40.173 so I'm going to suggest that 41 times line height.